ABSTRACT
Objective To investigate the CT features of nodular or mass-like type pulmonary cryptococcosis(PC). Methods A total of 52 cases with nodular or mass-like type PC confirmed by pathological examinations at Fuzhou Pulmonary Hospital of Fujian from January 2008 to December 2012 were studied. Each patient underwent a breath-hold MSCT scan and contrast enhanced CT was performed in 19 patients. The data including lesion size, number, distribution, density, performance of enhanced CT scan and accompanying signs were analyzed. Each CT accompanying sign was compared between nodular lesions and mass-like lesions using χ2 test,continuous correction χ2 test or Fisher exact test. Results Of all the 52 patients, pulmonary cryptococcosis was consisted single nodules/masses (21 cases) and multiple of nodules/masses (31 cases). There were total 206 lesions with 172 nodules and 34 masses. The lesions were mainly found in lower lobe(73.3%, 151/206)and outer zone or subpleura(87.4%, 180/206)of lung. Plain CT scan showed the densities of most lesions were solid and uniform(74.7%, 154/206). A total of 95 lesions were detected in the 19 patients with contrast enhanced CT, in which 61 lesions (64.2%) showed homogeneous enhancement and 86 lesions (90.5%) showed moderate enhancement. Nodular or mass-like lesions accompanied by many CT signs including halo sign (59.2%, 122/206), air bronchogram (32.0%, 66/206), pulmonary cavity or vocule sign (15.0%, 31/206), lobulation sign (25.2%, 52/206), spicule sign (13.1%, 27/206), pleural indentation(7.8%, 16/206) and vascular cluster (1.9%, 4/206). Compared with mass-like lesions, lobulation sign was more frequently observed in nodular lesions(χ2=13.750, P=0.001), whereas air bronchogram and pulmonary cavity orvocule sign were less frequently observed(χ2=19.957, P=0.001; χ2=5.295, P=0.021, respectively). No significant statistically differences were detected in other CT signs between them (P>0.05). Conclusions PC lesions usually occur in right lung, lower lobe and close to the pleura. Halo sign and air bronchogram are the characteristic findings of CT manifestations in nodular or mass-like type PC.